1. Field of the Invention
This invention relates to novel liquid crystal compounds and liquid crystal compositions containing the same.
2. Description of the Prior Art
Liquid crystal display elements utilize the optical anisotropy and dielectric anisotropy of liquid crystal substances and are classified into TN type (twisted nematic type), DS type (dynamic scattering type), guest-host type, DAP type, etc. according to their modes based on principle. Due to differences between these modes, the optimum characteristics of liquid crystal substances suitable to their respective uses are different. At any rate, however, it is common to these liquid crystal substances that they are required to be stable to moisture, air, heat, light, etc. Further, they are required to be capable of existing in the form of a liquid crystal phase at least in the range of 0.degree. to 60.degree. C. However, no single compound exists which satisfies all of these conditions, but it is the present status that mixtures of several kinds of liquid crystal compounds or nonliquid crystal compounds have been practically used as a liquid crystal composition.